著者

阿部 司 鬼倉 徳雄 中島 淳

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.62, no.1, pp.65-69, 2015-04-25 (Released:2017-08-10)

参考文献数

33

著者

井上 太之 鈴木 大 北野 忠 河野 裕美

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.68, no.1, pp.29-34, 2021-04-25 (Released:2021-05-09)

参考文献数

22

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Compared with the other anguillid eel species native to Japan (Anguilla japonica and A. marmorata), very little is currently known about the Japanese populations of A. bicolor pacifica. Three specimens of the latter (652.4–879.1 mm total length), collected in an irrigation channel on Iriomote Island, southern Japan, were examined, and the phylogenetic and morphological characters of the species discussed. The stomach contents of two specimens included a number of frog remains.

著者

上原 匡人 本永 文彦 太田 格 海老沢 明彦 宮岡 勇輝 立原 一憲

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

2021

---

<p>The Indian mackerel <i>Rastrelliger kanagurta</i> is an important coastal fishery resource for Okinawa Prefecture, southwestern Japan. However, much is still unknown about its life history. The early development, occurrence, sexual maturation, and reproductive cycle of the species was examined from specimens collected from the coastal waters of Okinawa Island, and management of the fishery evaluated. Larvae [3.4 mm notochord length–12.5 mm standard length (SL)] and juveniles (11.4–16.2 mm SL) of <i>R. kanagurta</i> were distinguished from other mackerel species by: 1) numbers of myomeres, 2) absence of spines on the preopercle posterior margins, 3) positional relationship between the upper and lower jaw tips, 4) melanophore pattern, and 5) distribution (allopatric). Both larvae and juveniles occurred in the offshore epipelagic zone of Nakagusuku Bay in May, June, and August, which coincided with the occurrence of high-gonadosomatic value adults in coastal waters. However, specimens were not encountered in extremely shallow coastal areas (e.g., tidal flats), although younger individuals may utilize such the offshore epipelagic zone of the bay, attaining fork lengths (FL) of ca. 8 cm. Individuals mature at ca. 26 cm FL, one year after hatching. <i>R. kanagurta</i> are primarily caught by set net fishery near Okinawa, small (immature) individuals accounting for > 45% of netted individuals in all months, except May and June, during the period from April 1985 to April 1987, and for > 35% of the examined individuals in all months, except June and July, between April 2011 and March 2016. These results for both periods suggest growth overfishing. Accordingly, immature individuals must be conserved to sustain the Okinawan population of <i>R. kanagurta</i>.</p>

著者

片野 修 馬場 吉弘 河村 功一 大原 均

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.62, no.2, pp.99-106, 2015-11-05 (Released:2018-03-26)

参考文献数

30

被引用文献数

3

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Nonbenthic fishes were investigated in 16 rivers in the Chubu and Tohoku regions, into which pale chub Zacco platypus had been introduced. Pale chub coexisted predominantly with Japanese dace Tribolodon hakonensis, followed by ayu Plecoglossus altivelis altivelis, and were abundant in rivers lacking the latter. Although pale chub, ayu, Japanese dace, dark chub Nipponocypris temminckii and Amur minnow Rhynchocypris lagowskii steindachneri all fed on both benthic algae and invertebrates, the percentage of algae in the diet of pale chub was less when ayu were present. However, the population abundance and diet of pale chub were not affected by the other nonbenthic species. Although pale chub and other cyprinids rarely fed on cyanobacteria, a main food item of ayu, pale chub was considered to be negatively affected by ayu through interference, exploitative competition and indirect effects via changes in algal composition.

著者

鈴木 寿之 森 誠一

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.63, no.1, pp.39-43, 2016-04-25 (Released:2018-04-25)

参考文献数

17

被引用文献数

1

著者

上原 匡人 太田 格 海老沢 明彦 立原 一憲

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

2021

---

<p>Two closely related, commercially important threadfin breams, <i>Nemipterus furcosus</i> and <i>N. peronii</i>, are an essential coastal fishery resource in Okinawa Prefecture. The age, growth, reproductive cycle, and stomach contents from 124 <i>N. furcosus</i> and 37 <i>N. peronii</i>, obtained from November 2011 to December 2015, were examined, age being assessed from sectioned otoliths and gonadal histology. <i>Nemipterus furcosus</i> and <i>N. peronii</i> were the most abundant threadfin breams in Kin Bay and Nakagusuku Bay, Okinawa Island, areas including many coastal tidal flats, where the two species comprised 98.1% of the total number of <i>Nemipterus</i> individuals examined. Overall sex ratios of both species were significantly sex-biased, the apparent lack of transitional gonads implying functional gonochorism. The spawning seasons of both species were estimated as occurring between spring and fall, no immature fishes having been obtained. Age validation using edge-type analyses implied that opaque zones were formed once per year, being valid annual growth increments. Although no intersex differences in maximum length, growth equation, and age range were observed in <i>N. furcosus</i>, <i>N. peronii</i> females were larger and older than males. The greatest ages observed were 4.3 and 7.0 years for <i>N. furcosus</i> and <i>N. peronii</i>, respectively. Both species fed predominantly on crabs, which primarily occupied the inner bays. Over the previous 27 years, the catch per unit effort of <i>Nemipterus</i> has declined in the highly altered environments of Kin and Nakagusuku Bays, suggesting that the decline in the populations of these species at Okinawa Island may be due to coastal fishery practices, environmental decline, and the degradation of suitable habitats. The biological implications for conservation are discussed.</p>

著者

佐藤 真央 井上 裕太 溝脇 一輝 小林 大純 松尾 怜 外山 太一郎 日比野 友亮

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.68, no.1, pp.17-22, 2021

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<p>Twelve specimens (71.5–89.9 mm standard length) of the genus <i>Lutjanus</i> (Lutjanidae), collected from Ishigaki-jima Island, Ryukyu Archipelago, southern Japan, were identified as <i>Lutjanus biguttatus</i> (Valenciennes in Cuvier and Valenciennes, 1830), being characterized by the following combination of characters: dorsal fin XI, 12; anal fin III, 8; pectoral rays 15–16; body depth 3.5–3.8 in standard length; preorbital depth 10.8– 16.3 in head length; tongue smooth, without patch of fine granular teeth; a dark longitudinal band from snout to caudal fin base; and two white spots above the lateral line. Dentition of the premaxilla and dentary, including several canine-like (one being long and curved) and many small conical teeth, is illustrated. The collected specimens were determined to be juveniles, due to their coloration matching that of juveniles previously described, in addition to their small body size. Although the coloration of <i>L. biguttatus</i> is similar to that of <i>L. vitta</i> during the juvenile stage, the latter species is distinguished by greater body and preorbital depths. The specimens of the former had been caught in a significantly localized area (in ca. 4 m depth) over several days, indicating the likelihood of their having been schooling, as observed in previous studies of the species. <i>Lutjanus biguttatus</i> is distributed in the Indo-western Pacific, from the Maldives to the Solomon Islands, but had not previously been recorded from Japanese waters. The new standard Japanese name "Futahoshi-fuedai", given in reference to the two white spots above the lateral line in the collected specimens, is proposed.</p>

著者

中村 潤平 本村 浩之

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

pp.21-001, (Released:2021-04-30)

参考文献数

25

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The threadfin bream genus Nemipterus Swainson, 1839 (Perciformes: Nemipteridae) currently includes 29 valid Indo-West Pacific species, eight of which have been recorded from Japanese waters. During an ichthyofaunal survey of Tanega-shima Island, Osumi Islands (Kagoshima Prefecture), Japan, a single specimen (246.9 mm standard length) of the Japanese Threadfin Bream Nemipterus japonicus (Bloch, 1791) was collected at a depth of 10 m on 13 January 2020. The specimen was characterized by seven anal-fin soft rays, 47 lateral-line scales, 6 + 10 = 16 gill rakers, a moderately deep body (depth 33.9% of standard length), long pectoral fin (posterior tip vertically level with anal-fin origin), posterior tip of depressed pelvic fin reaching between anus and anal-fin origin, upper lobe of caudal fin filamentous, and body pinkish dorsally and silver ventrally, with 1 longitudinal yellow stripes on the lateral surface, and a reddish blotch on the lateral line above the pectoral fin. Although the species is widely distributed in tropical and subtropical Indo-West Pacific waters from the Red Sea and the east coast of Africa to Taiwan and the Malay Archipelago, and bears the specific and Japanese names japonicus and Nihon-itoyori, respectively, it has at no time been recorded from Japanese waters. Therefore, the present specimen of N. japonicus, described here in detail, represents the first reliable record from Japan and northernmost record of the species in the western Pacific Ocean. The specimen collected from Tanega-shima Island was most likely to have been transported from Taiwan or the Philippines by the Kuroshio Current, the species being unlikely to reproduce in Japanese waters.

著者

髙見 宗広 遠藤 広光 福井 篤

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

pp.21-010, (Released:2021-05-10)

参考文献数

13

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The alepocephalid genus Conocara Goode and Bean, 1896 is characterized by the dorsal-fin origin located posterior to the anal-fin origin, dorsal-fin base shorter than the anal-fin base, body covered with small scales (> 80 in longitudinal row above the lateral line), tubular lateral line scales, the maxilla toothless, upper jaw equal to or longer than the snout, and photophores absent. Six specimens of Conocara werneri Nybelin, 1947, collected from Hyuga-nada Sea, Japan in a depth of 1,453–1,481 m, on 3 April 1991, are distinguished from all congeners by the following combination of characters: 17–20 dorsal-fin rays, 30–34 anal-fin rays, 159–179 longitudinal series scales above the lateral line, 19–22 scales between the dorsal fin insertion and lateral line, 25–32 scales between the anal fin insertion and lateral line, premaxillary bony crests present, the upper jaw reaching a vertical through the orbit anterior margin, an uninterrupted inner row of gill rakers on the first gill arch, the absence of palatine teeth, and raised insertions of the dorsal and anal fins with well-developed anterior cariniform skin folds. The gut contents of the six specimens represented the following higher taxa: Amphipoda, Copepoda, Ostracoda, Gastropoda (conch), Diatoma, Pyrosomata, and Foraminiferida. Four specimens possessed 113–550 developed ovarian eggs (maximum diameter 4.6 mm). Conocara werneri has been recorded previously only from subtropical zones of the eastern Atlantic and off New Zealand (south-western Pacific), the present specimens therefore representing the first record of the species from Japanese waters and northernmost record in the Pacific Ocean. The new standard Japanese name “Sedaka-yajiri-iwashi” is proposed for the species.

著者

松沼 瑞樹 本村 浩之

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.56, no.1, pp.21-30, 2009 (Released:2014-03-04)

参考文献数

19

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The Shortfin Molly, Poecilia mexicana, is herein reported for the first time from Japan on the basis of specimens collected from the Nitanda River (hot spring water) in Ibusuki City, Kagoshima Prefecture. The fish from Ibusuki City, previously misidentified as P. sphenops, is believed to represent an introduced population from the west coast of Central America (original locality of the species) or other places. Poecilia mexicana is characterized by having 9 dorsal- and anal-fin soft rays, 18 caudal-peduncle scales, unicuspid upper-jaw inner teeth, sensory pores on the dorsal surface of the snout, and the broad vertical orange band on the caudal fin in mature males. Morphological changes with growth and sexual dimorphism of Japanese P. mexicana are also described. A new Japanese name “Surikogi-mori” is proposed for the species.

著者

日比野 友亮

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.64, no.1, pp.59-64, 2017-04-25 (Released:2018-06-01)

参考文献数

16

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A single specimen of the catfish, Silurus lithophilus (Tomoda, 1961), was found in the collection of the Natural History Museum, London. The catalog number of the specimen (BMNH 1910.6.30.18) indicates that it was registered on 30 June 1910, long before the collection of the holotype of S. lithophilus (April 1961), previously believed to be the first collected example of the species. Accordingly, the Natural History Museum specimen represents the oldest known example of the species. It is inferred that the specimen was collected during the 6th collecting survey of Mr. Richard Gordon Smith (from November 1905 to mid 1907), the precise date not being apparent in his excerpted diary published by Ms. Victoria Manthorpe. The collection locality of the specimen was noted as Kyoto on the jar label and in the museum collection database. However, a personal tag attached by Mr. Gordon Smith noted its collection from Lake Biwa. Apparently, the specimen was purchased at Kyoto after having been originally collected at Lake Biwa.

著者

髙橋 夢加 岡田 誠 笹木 大地 本村 浩之 木村 清志

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.65, no.2, pp.181-185, 2018-11-05 (Released:2018-11-05)

参考文献数

11

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The carangid genus Decapterus Bleeker, 1851 is characterized by single finlets behind both the second dorsal and anal fins, no scutes along the anterior curved part of the lateral line, two low papillae on the shoulder girdle, and a well-developed adipose eyelid. Members of the genus are distributed in tropical to temperate areas of the Pacific, Indian and Atlantic oceans, and are commercially important food fishes. Four species (D. akaadsi Abe, 1958, D. kurroides Bleeker, 1855, D. smithvanizi Kimura, Katahira and Kuriiwa, 2013 and D. tabl Berry, 1968), characterized by a red caudal fin, are included in the red-fin Decapterus group. In 2016 and 2018, three specimens [216–304 mm in standard length (SL)] of D. kurroides, previously recorded from the Red Sea and east coast of Africa to the east coast of Australia and the Philippines, were collected from Kumano-nada, Pacific coast of Mie Prefecture, Japan. Additionally, a single specimen (191 mm SL) collected from Japanese waters in the East China Sea (west of Kyushu) in 2006 was also identified as D. kurroides. The specimens represent the first records of the species from Japanese waters, the Kumano-nada specimens being the northernmost record for the species. Decapterus kurroides is the most similar to D. akaadsi, but differs from the latter in the following characters: scutes more numerous on the straight part of the lateral line (30–32 vs. 26–29 in D. akaadsi), longer head (head length 29.9–33.0% SL vs. 26.7–30.1%) and longer snout-anus distance (55.8–60.4% SL vs. 51.2–54.6%) [measurements for both species modified from Kimura et al., (2013)]. Decapterus kurroides is also distinguishable from D. smithvanizi and D. tabl by having fewer cycloid scales on the curved part of the lateral line (45–52 vs. 54–62 in D. smithvanizi, 61–72 in D. tabl) and a deeper body (body depth 23.4–27.2% SL vs. 19.4–22.5%, 16.6–23.0%). A new standard Japanese name “Kitsune-akaaji” is proposed for D. kurroides.

著者

日比野 友亮 笹木 大地 木村 清志

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.63, no.1, pp.33-38, 2016-04-25 (Released:2018-04-25)

参考文献数

14

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The cosmopolitan genus Opistognathus Cuvier, 1816, characterized by unforked dorsal-fin spines, currently comprises 64 valid species, including Opistognathus variabilis Smith-Vaniz, 2009, described on the basis of 71 specimens and widely known from the Maldives, Andaman Sea, Indonesia, Philippines, Palau, Taiwan, Ryukyu Islands and Vanuatu. However, the Japanese record was based solely on an underwater photograph taken off Iriomote Island, Ryukyu Islands. A single example of the species, collected from Yonaguni Island, Yaeyama Islands, represents the first record of the species from Japan supported by a voucher specimen. Opistognathus variabilis closely resembles Opistognathus albicaudatus Smith-Vaniz, 2011 and Opistognathus castelnaui Bleeker, 1860 in having an elongate upper jaw, numerous longitudinal scales and similar body coloration, including 7–10 dark blotches along the dorsal-fin base. However, the former can be distinguished from O. albicaudatus by the poreless Y-shaped area dorsally on the head (vs. absent) and 9–11 procurrent caudal-fin rays (vs. 6–7), and from O. castelnaui by having 68–92 longitudinal scale rows (vs. 90–110), the dorsal fin deeper posteriorly (vs. similar depth along entire length), a single stripe on the upper jaw inner surface (vs. two), and seven or eight mid-lateral blotches along the body (vs. three or four irregular dark horizontal lines and/or dark reticulations laterally on body). The new Japanese standard name “Shishidama-ohkuchi-amadai” is proposed for O. variabilis.

著者

鹿野 雄一 山下 奉海 田中 亘 小山 彰彦 菅野 一輝

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.64, no.1, pp.43-53, 2017-04-25 (Released:2018-06-01)

参考文献数

41

被引用文献数

1

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The current distribution of the Japanese eel Anguilla japonica and giant mottled eel A. marmorata were surveyed in 1120 inland water bodies on mainland Kyushu and the Nansei Islands, southern Japan. Anguilla japonica occurred at 8 and 2 sites on Kyushu and the Nansei Islands, respectively, the low catch rate apparently reflecting its cryptic life style. The likelihood of occurrence of A. japonica in stream habitats on the Nansei Islands was significantly lower than on mainland Kyushu. Anguilla marmorata occurred at 46 sites (mostly streams) on the Nansei Islands. Accordingly, low stream occurrence of A. japonica on the Nansei Islands may have resulted from interspecific competition. An informal verbal survey of 359 local respondents indicated that A. japonica had formerly been plentiful in Nansei Islands paddy fields, although a similar survey on mainland Kyushu found the habitat of A. japonica to be streams, rivers and/or estuaries. Local names of A. japonica on the Nansei Islands, including “paddy-dwelling eel” and “mud-dwelling eel”, also indicated adaptation of A. japonica to a paddy environment, the use of “stream-dwelling eel” for A. marmorata further suggesting habitat segregation of the two species. The paddy environment appears to be the primary habitat of A. japonica on the Nansei Islands. However, such paddy fields have decreased significantly in extent due to a recent crop change to millet. Restoration of the paddy environment is essential for future A. japonica conservation on the Nansei Islands.

著者

後藤 暁彦 黒木 真理 森田 健太郎

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.67, no.2, pp.241-245, 2020-11-05 (Released:2020-11-14)

参考文献数

20

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A non-native brown trout Salmo trutta (407 mm in fork length, 717 g in body weight) was collected from the Otsukushinai River, southern Hokkaido, Japan, in 2019. This specimen was an immature male (0.4 g in gonad weight). The otolith Sr:Ca ratio profile and annual rings suggested that the specimen had migrated to the sea at the age of 4+ years and ascended the Otsukushinai River in the year of the seaward migration. This study is the first record of invasion of anadromous brown trout through the sea in Japan.

著者

佐藤 初 坂井 陽一 桑村 哲生

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

2020

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<p><i>Aspidontus taeniatus</i> (Blenniidae) mimics the bluestreak cleaner wrasse, <i>Labroides dimidiatus</i> in both shape and color. We found a small brownish color variant of <i>A. taeniatus</i>, which was suitable for testing the effect of mimicry. Comparison with the feeding behavior of typically-colored individuals indicated no significant differences between the two in feeding frequency (bites on tubeworm tentacles, boring-clam mantles, and fish fins), suggesting that coloration had no effect on such activity. It is likely that the abundant availability of the former two benthic foods on the study reef may have caused the very low frequency of fin biting, which may have resulted in no differences between the two color patterns.</p>

著者

河合 俊郎

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.64, no.2, pp.175-178, 2017-11-25 (Released:2018-06-19)

参考文献数

7

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Armored searobins in the Indo-West Pacific genus Paraheminodus Kamohara, 1958 (Peristediidae), characterized by upper jaw teeth, the lateral head margin smooth, posterior pairs of lower lateral row bony plates separated from each other, and unbranched barbels on the lower jaw (except for posteriormost lip and chin barbels), include four species: Paraheminodus laticephalus (Kamohara, 1952), P. murrayi (Günther, 1880), P. kamoharai Kawai, Imamura and Nakaya, 2004 (known only from a single record from the Sulu Sea, Philippines) and P. longirostralis Kawai, Nakaya and Séret, 2008. To date, only P. laticephalus and P. murrayi have been recorded from Japan. However, a single specimen of P. kamoharai (114.2 mm in standard length) collected from Kochi, Japan, was found in the collection of Kyoto University, Japan, being the second record of the species and first from Japanese waters. Paraheminodus kamoharai is re-diagnosed, having 5+1+17– 20=23–26 gill rakers, rostral projection length 42.5–47.0% of head length, upper jaw length 40.5–42.3% of head length, lower jaw length 36.5–37.7% of head length, pectoral fin length 57.5–66.4% of head length, preopercular spine length 34.9–40.9% of head length, distance from anus to caudal fin 46.9–49.3% of standard length, and both forwardly and backwardly directed spines on the posterior upper lateral row bony plates. The new Japanese standard name “Kamohara-kihoubou” is proposed for the species.

著者

加藤 柊也 丸山 智朗 乾 直人 後藤 暁彦 鈴木 寿之 瀬能 宏

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

pp.19-031, (Released:2020-02-28)

参考文献数

19

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Eighteen specimens of the pipefish Microphis retzii were collected from several rivers on Iriomote and Ishigaki Islands (Yaeyama Islands, Ryukyu Islands, Japan) from 1990 to 2019. The records from Iriomote Island, including variously sized specimens plus brooding males over multiple years, suggest established settlement of the species. The records from Ishigaki Island, being the first specimen-based records of the species from that locality, are suggestive of a new settlement. Accordingly, M. retzii should be treated as a Japanese resident species, rather than one subject to abortive migration, making them eligible for evaluation of red lists in Japan.

著者

石井 文子 安齋 有紀子 伊藤 玲香 小山 直人 北川 忠生

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.58, no.1, pp.65-74, 2011 (Released:2014-03-07)

参考文献数

19

被引用文献数

1

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The Yoshino diversion (Yoshino Bunsui) was established to supply irrigation water from the Yoshino River to the Yamato plain. In order to examine fish introductions through the canals of the Yoshino Bunsui, the genetic structure of 17 populations of dark chub Zacco temminckii collected from the Yamato and Yoshino rivers were analyzed and their mtDNA ND2 sequences studied. A total of 16 haplotypes were detected in 261 individuals, 6 haplotypes being present in both rivers. In the Yamato River, the shared haplotypes were found to be associated with the locations of inflows from the Yoshino Bunsui. On the other hand, the majority of haplotypes found in individuals from the Yamato River were not found in those from the Yoshino River. This study confirmed the secondary introduction of dark chub from the Yoshino River into the Yamato River via the Yoshino Bunsui.

著者

岡本 誠 倉石 信 藤井 芳 森 俊彰

出版者

一般社団法人 日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

pp.20-003, (Released:2020-05-29)

参考文献数

28

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Fertilized eggs of two manefishes (Caristius macropus and Paracaristius nudarcus) were collected off Shionomisaki, Wakayama Prefecture, Japan and hatched in an aquarium. Descriptions are provided for early-life stages of both species [C. macropus (6 specimens: 8.9–125.9 mm in standard length: SL; maximum rearing period 255 days) and P. nudarcus (26.8 mm SL; 64 days)], based on the reared larval and juvenile specimens. Characters known to be diagnostic for the genus Caristius, including small sized lateralline scales and serrated lower caudal-fin rays, appeared from 80.9 mm SL in juvenile C. macropus. Juveniles of the two species differed in dorsal fin shape and meristic characters. The occurrence of fertilized eggs in waters off Wakayama Prefecture, Japan indicated that C.macropus and P. nudarcus both spawn in Kuroshio waters.